Numerous tube or pipe couplings or fittings are known in the art, some of them which have quick connect and quick disconnect features. Examples are found in many patents, some typical ones being those noted here. U.S. Pat. No. 4,124,235--Grahl et al, issued in November, 1978, is typical of a threaded body and nut arrangement having a wedge-like metal sleeve which is tightened in gripping relation with a tube extending therethrough as the nut is threaded on the external threads of the body. U.S. Pat. No. 1,615,233--Redlinger, issued in January 1927, is typical of some cantilever clamping action fittings using tapered threads to cause the cantilever clamps to engage the pipe or other cylindrical member being gripped. U.S. Pat. No. 4,544,186--Proni, issued in October of 1985, shows a similar clamp action fitting in which a fitting body has split ends provided with external threads. An internally threaded nut is threaded over the split ends. When the nut is threaded on the split ends until it bottoms out on a flange on the fitting body, the threads force the main body split ends into clamping engagement with a tube or pipe. U.S. Pat. No. 3,499,671--Osborne, issued in March of 1970, shows another coupling for a tube without using flared ends, and includes a deformable metal sleeve between a nut and body having threaded engagement with each other.
It is typical of such prior art when threads or other camming surfaces are used that the threads or camming surfaces are exposed to contaminants or physical damage during handling and transport, as well as while being used as a coupling or connector. Others are not preassembled, and then attached to cylindrical members in clamping fashion without some disassembly or with only a minimum of securing action. Some do not provide adequate sealing arrangements to handle higher fluid pressures in the tubes or pipes which are connected by them.
In the patent application noted above and of which this application is a continuation-in-part, a nut main body has internal camming surfaces formed by on a bore or recess inner surface. A cap bolt has a through bore, a bolt head, and a longitudinally segmented shank defining axially extending clamping legs. External camming surfaces, defined by threads on the ends of the clamping legs which are remote from the bolt head, fit within the internal camming surfaces of the nut main body with the bolt head engaging the nut main body so that the internal and external camming surfaces are contained within the nut main body and protected against physical damage during transport and handling. A cylindrical member, which may be a pipe, tube, rod or other device, fits through the cap bolt bore in snug but relatively movable relation, and extends at least into the nut main body recess axially beyond the internal camming surfaces. It is preferred that the nut main body have a passage or bore of which the recess having the internal camming surfaces are a part, with the cylindrical member extending at least partially into the nut main body passage or bore axially inward of the recess internal camming surfaces. The cap bolt is then further tightened, but cannot move axially further into the recess because of the engagement of the bolt head and the end of the nut main body. This causes camming action of the camming surfaces to occur, creating forces acting radially inward on the clamping legs at their ends with the external camming surfaces formed thereon, causing them to be resiliently bent in cantilever fashion to clampingly grip the cylindrical member. It is preferred that suitable seals be provided to keep the camming surfaces further protected, and to hold fluid pressures which may later be introduced into the pipe, tube or other fluid-conducting cylindrical member. It is also preferred that stop means be provided in the nut main body to locate the end of a cylindrical member at the appropriate position in the nut main body. Such stop means may be one or more shoulders positioned for abutting relation with the end of cylindrical members, or a removable C-clip in an internal groove in the passage or bore of the nut main body, or the end of another cylindrical member already positioned and clamped in place in the nut main body. The last noted stop means is particularly effective when two cylindrical members of different outer diameters are being connected by a fitting embodying the invention, with the larger one of the cylindrical member ends acting as an abutting stop for the smaller one, the larger one having been previously located by a shoulder in the nut main body passage or bore.